Vehicle location detecting system

Abstract

A vehicle location detecting method for detecting the location of a vehicle within a predetermined area, comprising the steps of: outputting distance data at every predetermined interval, the distance data being representative of the distance that a vehicle has traveled, outputting heading angle data at every predetermined interval, the heading angle data being representative of the heading angle change of vehicle travel, storing road map data representative of roadways, computing a present location data from the distance data and the heading angle data, and a limit error of the present location data which is determined by errors in the distance data, in the heading angle data and in the road map data, and registering locations on the roadways, which roadways are located within the limit error of the present location data, as estimate locations, computing correlation coefficients corresponding to the registered estimate locations, and selecting a correlation coefficient whose error is smallest with respect to the roadway from the computed correlation coefficients and outputting the registered estimate location corresponding to the selected correlation coefficient as a present location.